Any problems using a switch on the lamp side of a Ballast?
I have a 18 W low pressure sodium lamp that is powered by a magnetic ballast. Looks like a simple inductor with a power correction capacitor (photo from old prototype box):
The lamp is then on about 4m of cord to a pendant floor lamp (heh, who says LPS isn't suitable for indoor lighting), that happens to have a inline switch.
Now with this switched off the lamp is effectively taken out of the circuit, but the Ballast and Capacitor are still powered. Is this a problem?
I have trialled it. The Ballast stays cold. However if you use a cheap Power-Watt meter it says it's using about 80Watt! power factor 100%.
This is in contrast to normal running conditions where it reads 25 Watt, 97% power factor. I tried looking at the power meter in the switch box, but on/off/unplugged seemed to have no visually measureable effect.
I have a 18 W low pressure sodium lamp that is powered by a magnetic ballast. Looks like a simple inductor with a power correction capacitor (photo from old prototype box):
The lamp is then on about 4m of cord to a pendant floor lamp (heh, who says LPS isn't suitable for indoor lighting), that happens to have a inline switch.
Rich (BB code):
switch
|-------/+-------------_______---A
| ----|Ballast|
Lamp Cap | |_______|
| =
|-------/+--------|------------- N
Now with this switched off the lamp is effectively taken out of the circuit, but the Ballast and Capacitor are still powered. Is this a problem?
I have trialled it. The Ballast stays cold. However if you use a cheap Power-Watt meter it says it's using about 80Watt! power factor 100%.
This is in contrast to normal running conditions where it reads 25 Watt, 97% power factor. I tried looking at the power meter in the switch box, but on/off/unplugged seemed to have no visually measureable effect.